GST Calculator
Add or remove sales tax, GST or VAT from any price.
1,000Price before tax
180Tax
1,180Total
About the GST Calculator
Use this calculator to work out sales tax, GST or VAT on a purchase or invoice. You can add tax to a price that does not include it, or take tax out of a price that already includes it, and see the price before tax, the tax amount and the total.
How to use the GST Calculator
- Enter the Amount.
- Enter the Tax rate as a percentage.
- Choose Add tax to price, or Price already includes tax.
- Read the price before tax, the tax and the total.
Good to know
- The rate of 18 shown at the start is only an example. Enter the rate that applies to your product, country and date, because tax rates and exemptions change.
- To remove tax, the calculator divides the total by 1 plus the rate. For example, 1,180 with 18% tax included is 1,000 before tax.
- Do not subtract the percentage from the total directly. That gives the wrong answer because the tax was added on the smaller price.
Frequently asked questions
What is the difference between GST, VAT and sales tax?
They are all taxes on sales. The names and rules differ by country, but the maths for adding or removing the tax is the same.
Can I use it for an invoice?
It gives a quick check. For official invoices, follow the rules of your tax authority and your accountant.
Does it round the result?
Results are shown with up to two decimal places.